I arrived in Arizona yesterday all geared up for what is to be a tremendous weekend of baseball, fantasy baseball, and prospect watching.

First Pitch Arizona, established 17 years ago by fantasy baseball god Ron Shandler, got under way Thursday evening. The conferences don’t start until tomorrow, but we already have one Arizona Fall League game under our belts.

Thursday night, I was at Salt River Field at Talking Stick to view the Peoria Javelinas and Salt River Rafters. Below are some notes from the game, along with some video of some of baseball’s top prospects.

Seattle Mariners prospect Nick Franklin led of the game with a line-drive double to the left-center gap against Rafters’ starter Cody Scarpetta. Franklin had two hits in the game, but also made two errors at shortstop, one fielding and one throwing. Both miscues were plays that should have been routine outs.

Franklin is a difficult prospect to grasp. He displayed tremendous power for his size in 2010 (6-1/185 at best) while playing in the Midwest league (23 home runs), but he only managed five home runs in 64 games while playing in the hitter friendly California League, with home games at super hitter friendly High Dessert. I saw Franklin play in the Cal League this past summer and what I saw there, combined with what I saw last night, leaves me far from impressed. His swing itself is uncomplicated enough, but he does rely on a drastic weight shift forward to generate power. That leaves him susceptible to good offspeed pitches. He made 22 errors last season and many have wondered whether he should shift to second base, or even possibly center field. Unless he improves defensively, he’s not going to play as an everyday shortstop in the big leagues.

Franklin’s not a plus runner either. He stole 25 bases in 2010, but those numbers dropped this past season and I expect that they will continue to drop at the higher levels. I say his stolen base totals top out at 20 in the big leagues.

As for Cody Scarpetta, the pitcher that allowed the leadoff double to Franklin, he had a night to forget. With almost no control whatsoever, Scarpetta was pulled after allowing seven earned runs on five hits and two walks while only managing to get one out.

Nolan Arenado was the one prospect in Thursday night’s game that I was most excited to see. At high-A Modesto in the Cal League, Arenado hit .298/.349/.487 with 20 home runs in 583 plate appearances. He struck out only 53 times all season and has the potential to put up solid power numbers as a future fantasy third baseman. Arendao went 2-5 to raise his AVG to a lofty .384 during the AFL.

As good as his numbers have been throughout this year, I have a small concern with his approach at the plate. His contact skills are so good that sometimes he seems to swing at pitches outside the strike-zone too often, knowing that he can hit them anyway. He also tends to lunge at the ball, shifting all of his weight forward, which could lead to issues with good offspeed stuff and negate future power potential.

While it’s hard to argue with the results, there is certainly some chink in his armor that could be exposed against better pitching.

Cardinals first base prospect Matt Adams has moved his name up depth charts quickly over the past two seasons due to his tremendous production at the plate. This past season, Adams hit .300/.357/.566 with 32 home runs in only 115 games. He’s a big-bodied lefty that has plenty of natural power and some have dubbed him as Albert Pujols’s replacement should the all-star first baseman sign elsewhere as a free agent.

Adams has a wide base and doesn’t put too much movement into his swing, which helps him keep his strikeout totals down. His hands move very little as he begins his swing, but some reports say that he can get long by dipping his back shoulder. He could have issues against left-handed pitching throughout his big league career. Not many people project him to his for much AVG/OBP at the big league level, but the power is “build in” to his frame. Defensively, he looked fine with the glove on the several grounders he fielded Thursday night, though his range will never be an asset.

Quick hits…

This was my first chance to see Padres power prospect, Jaff Decker, in person. After the night was over, I couldn’t help but keep thinking about a Nick Siwsher comp, both in terms of size and swing. Decker is a walks machine and last night was no different. He went 0-2 with two walks and has a .432 OBP in the AFL.

Diamondbacks outfield prospect Adam Eaton went 2-5, but really impressed me with his baserunning and presence on the field. Eaton is small, 5-9/180, maybe, but he gives you the impression that he know’s he’ll be a big league ballplayer. He has good speed and the skills at the plate to his for AVG and get on base. He probably won’t be a huge impact player at the big league level, but he’ll be the kind of player that fans will fall in love with.

I didn’t really have Mets third base prospect Jefry Marte on my radar, but I overhear a couple scouts saying good things about him. He went 2-3 with a home run, his fourth round tripper of the AFL. They kept shouting, “Show me something!” and he did.

Cardinals prospect Oscar Tavares hit an absolute moon shot over the right field wall in the ninth inning and when I say moon shot, I mean a monster bomb that almost reached the concourse over the grass at Salt River Fields. Tavares is only 19 and before last season Baseball Prospectus’ Kevin Goldstein wrote,

“Taveras is an instinctual hitter who generates hard contact to all fields with a quick swing that incorporates plenty of strength from his core. He projects for average to plus power as his game and body matures.”

Based on what I saw, the plus power has already arrived. Taveras tore up single-A this past season to the tune of .386/.444/.584 with eight home runs in 347 plate appearances.